The long-term goals of this research are to determine the dynamic response of various oral microcirculations as a function of age, and the interactive effects of drugs, age, and disease on the dynamics of oral microcirculations. The specific aims of this p[articular proposal are to develop videomicroscopy or the study of the human gingival microcirculation and to characterize the gingival micro-circulation in healthy adults of three age groups, young (18-25 years), middle aged (35-45 years) and elderly (65-75 years) human subjects. In the first year of this project a head stabilization device will be designed and built to enable us to obtain stable videoimages of the gingival microcirculation, and an instrument will be purchased and computer software will be written for it which will allow analysis of videoimages with rhythmic movement due to cardiac contraction. Subjects involved in this phase will be 15 young adults (18-25 years). In the second year 20 subjects will be seen from each f the age groups mentioned above. An integrated videomicroscopy and computer analysis system will be utilized to obtain and analyze gingival microvessel erythrocyte velocity, vessel density (vessels/unit area), vessel activity (vessels exhibiting active flow/unit area), and vessel diameter. A computer operated physiography will be used to record and analyze systemic blood pressure, heart rate, electrocardiogram, arterial oxygen saturation, and end tidal carbon dioxide concentration. Also, early in the second year a laser doppler flowmeter will be purchased to allow us to measure total gingival flow for comparison with microvascular flow. Statistical analysis will include appropriate parametric and non- parametric analyses of variance to compare the three groups, as well as parametric and non-parametric measures of correlation between age and all other variables. In addition, stepwise regression analysis between all independent and dependent variables will be performed.